From vitamin D to mental health, read about the many health benefits of sunlight.

One day inside probably won’t hugely affect your health—but it’s not great to constantly stay cooped up from morning until dark. The biggest issue is that entering hibernation mode means you don’t get any exposure to natural light. Sunlight tends to improve your mood, and it helps your body produce vitamin D, which has been shown to help regulate the immune system, reduce inflammation in the body, and more. Sunlight also helps keep your internal body clock on schedule; your circadian rhythm plays a major part in regulating your appetite, sleep schedule, and energy levels. Research has shown that excessive exposure to electric lighting can throw off those internal rhythms.